Speed change device



, SPEED CHANGE DEVICE `Filed July l, 1937 4 Sheets-Sheet l g y 7 4/ z5.9i@ j@ 23 f4 Z7 l INVENTOR.

ATTORNEY.

May 3, 1938. J; D. CHRISTIAN 2,116,166

- SPEED CHANGE DEVICE Filed July 1, 1957 4 Sheets-Sheet 2 62V g 5/ ,l

Y i `-1 t. MV/ gg INVENTOR. Jofep/ Chris/isf? ATTO Mmes

May 3, 1938. J. D. CHRISTIAN SPEED CHANGE DEVICE Filed July 1,' 1937 4Sheets-Sheet 3 R. n Y. En, m m/fm A E E J May 3, 1938. J. D. CHRISTIANSPEED CHANGE DEVICE Filed July 1, 195'? 4 sheets-sheet .4 n

INVENTOR. Josep/7 (/7/7'5//5/7 ATTORNEY.

Patented May 3, 19378 Y `UNITED sla'ifEsv y SPEED CHANGE DEVICE JosephD.A Christian, San Francisco, application July 1, 1937, serai No.151,532

`8 Claims.

In myprior application Serial No.- 113,246, led November 28, 1936, Idisclosed a self contained speed change device adapted to be mounteddirectly upon a shaft of a driven unit, in combina-l supporting shaftwhich is in turn driven by the' speed change unit. .The structure shownin said application is further characterized in that a gear having anoverhanging face is utilized, this gear having a hub upon which isrotatably mounted the support casing. The connection between the gearhub and thesupport casing is by means of a bearing structure whichisvinserted and fits onto the hub beneath the overhanging gear face tothe end that thedevice is self contained, compact, and unit form,whether on or off the supporting shaft. This connection, the connectionbetween the gear hub and the supporting casing in said application, canbe either between an outside or an intermediate wall in the supportcasing. In this application I have disclosed the utilization of a gearhaving an overhanging face on both. sides of the gear web. 'I'he supportcasing for the entire device is mounted upon each side of the web ofthegear `to the end that the load of the support casing is adequatelydistributed over the gear hub while the device is compact, selfcontained and an assembled unit even when removed from the supportingshaft. A

It is the general object of the present invention to provide acommercially practical structure, one characterized by its simplicity indesign and manufacture so that a satisfactory structure can be turnedout at relatively low cost.

The invention includes other objects and features of advantage inaddition to ythe foregoing, some of which, together with the foregoing,will appear hereinaftenwherein the present preferred structure of thisinvention is disclosed.

In the drawings accompanying and forming a part hereof, Figure 1 is avertical section taken through the device embodying 'my invention.

Figure 2 is a fragmentary section illustrating a modified structure.

(Cl. I4-421) Figure 3 illustrates another modication particularlycharacterized in that it enables a light spun steel cover to beemployed, thus eliminating a considerable portion of the heavy castingsused heretofore in suchA units.

Figure 4 is a modification shown as a fragmentary section of thatstructure shown in Figure 3.

Figure 5 is a plan view, partly in section, illustrating in adiagrammatic manner an assembly of such a unit as that shown in sectionin Figure 3 in combination with a. motor or other prime mover. f

Figure 6 is a side elevation illustrating utilization of a unit whenassembled.

Figure 7 is a side elevation, partly in section,

of a portion of the assembly of the unit mounted in Figure 6.

In the drawings accompanying and forming apart hereof, I have shown'adriven unit generally at 6. From this unit a shaft l extends, this shaftbeing the power input element to the unit to be driven. This shaftsupports entirely the speed'change device to be presently described.

In accordance with this invention, the entire speed reducer unit ismounted upon the extending shaft, and the load thereof is borne by theunit 6. To effect this I provide upon the shaft 'I a gear generallyindicated at This gear includes a hub 9 mounted upon the shaft. The hub30 is secured to the shaft by a key II which is retained in place by setscrew I2. The gearhub 9 includes a gear web I0 intermediate the ends ofthe hub and the overhanging gear face.

In accordance with this invention, a suitable casing structure isprovided. This casing structure includes three members providing a rstwall I 6, a. second wall I Land a third wall I8. `'I'hese walls aresubstantially parallel to each other and are spacedapart with the secondWall Il between 40 the rst and third walls I6 and I8.

In Figures 1 andv 2'the members providing'walls II and I8 are shownassubstantially identical; they can be made from the same pattern.V As amatter `of fact, the only difference between the members" providingwalls` I6 and I8 in Figure 1 is that the inwardly extending boss, formedon Wall IB as a flange, is slightly longer than the correspondingboss-2| on member I8. 'This can of course be cared for in the pattern byproviding a removable section thereon. 'I'he flange I9 on member I6 andthe flange 2| on wall I8 are of course machined to suit the individualbearing units` associated therewith. The second or intermediate wall I'Iincludes a ange 22 thereon. 55

It is a feature of this invention that the flanges I9 and 22 extendtoward each other and provide 'mountings for bearing means 23 .and v24on oppo- 22 and the hub are best made with a coeilicient of expansionclosely approximating that of the casing. I have successfully used a'cast bearing structure made of bronze because I have found that, withthe construction disclosed, the unit pressure on the bearing is reducedto an extent.

suilcient to permit such a bearing to be employed successfully. `It isnot necessary to utilize ,expensive ball or roller bearings at thispoint with the construction disclosed although these are indicated at 25in Figure 3.

The three members (Figures 1 and 2) providing walls I6, I1 and I8l aresuitably secured together. To this'end, the intermediate wall member lisflanged as at 26. Upon this flange is formed a rim 21 opposite to thewall member itself, so that, in effect, an annular channel is providedabout the periphery of the structure which is substantially of a U crosssection. Bolts 28 are passed through suitable apertures and are receivedin flanges 29 and 30 respectively provided on members I6 and I8 tosecure the members together as a unit. A ring member is fitted into theannular channel as a cover.

' In accordance with my invention, I provide for mounting of the powerinput or drive shaft 36 in the casing in such a way that adequatesupport is provided therefor, and yet the total width of the unit is notincreased. To accomplish this, I provide a first bearing 31 in the wallI1, while a second bearing 38 is provided in the wall I8. These bearingsare shown as of the ball bea'ring type, although other types of bearingcan be used. y On the shaft 36 and intermediate the two bearings Iprovide a pinion gear 39. This gear can be either formed directly uponthe shaft 36 or `else formed separately and secured thereto.

It is to be noted in Figure 1 in the drawings that I have shown theshaft 1 slightly smaller than the shaft 36. However, this need not befollowed strictly, inasmuch as shaft 1 can be the same size as shaft 36and even larger as in Figure 3 wherein a receptacle 40 is formed forshaft 1.l However. having the shaft 36 relatively small in l diameterenables the gear 38 to be made likewise of small diameter, and greaterspeed change secured, since it is the comparative size of gears 39 and 8that determines in the end the primary reduction effected through theunit.

In Figures 2 and 4 I have shown shaft 36 as hollow, with the shaft 1extending therethrough. This is of course a permissible variation withinthe contemplation of the present invention, enabling the structure to bereadily employed for the driving of line shafts and the like. It isto befurther pointed out that whilethe present construction enables a hollowshaft 36 to be readily employed, other constructions in which hollowshafts are employed as the input shaft do not necessarily permit of theadvantageous construction shown in Figures land 3.

Mounted. upon the extending end of shaft 36 I have shown a suitablepower input means as chain 42 extending to a suitable prime mover, suchas a motor or the like, 16 in Figure 5. In

thewconstruction shown in Figure l, the input pulley 4I is shown at somedistance from the supporting device 6. 'Ihis means that the reactiveforce applied to drive the pulley 4I has a momentl about the bearingsprovided in structure 6 for shaft 1. Ordinarily this will not be of anyparticular consideration because the various units of the structure areso mounted that deflection between them cannot occur, and so that thewhole structure is adequately mounted upon shaft 1. However, in someinstances, consideration will have to be given to this factor, and inFigure 2 I have' shown a unit incorporating featuresl reducing themoment arm length about unit 6. In this structure I have shown the inputpulley 4I as provided adjacent tothe unit 6, and the shaft 36 hollow. Infact a slight clearance exists between the shaft 36 and shaft 1 andshaft 36 does not derive any support from shaft 1. This places the inputreactive force directly adjacent to the unit 6; the moment f the forceacting against the bearings supporting the shafts is relatively small ascompared to that moment which can exist when the structure is merelysupported after the manner of Figures 1 and 3.

I have heretofore mentioned that gears 39 and 8 were employed. Theserespectively constitute the first and second gears mentioned herein. To

` provide for the transmission of power between these gears, and toeffect the reduction in speed, I mount a shaft 46 in suitable bearings41 and 48 provided in walls I6 and I1. Shaft 46 carries a pinion gear-49 which engages gear 6. On the extending end of shaft 46 I mountanother gear 5I which meshes with gear 39. Gear 5I includes a hub 52thereon extending beyond theend of shaft 46. Within this hub I mount athrust bearing 53 to take up any thrust that may be placed upon shaft46. (Figure 1).

'I'he bearing 41 is mounted in a suitable re- '4 cept'acle 54 formedupon and extending from the wall I6. This receptacle also appears uponwall I6 in Figure 1, providing a'receptacle into which the hub 52 of thegear 5I is received without increasing the over-all width of the unit.

The members providing walls I6 and I8 are suitably flanged as at 56 tojoin the various portions -of the members together to ensure stability,strength and rigidity, and to provide adequate support vfor all thebearings in the unit.

In that construction shown in Figures 3 and 4, Wall I8 is mounted upon agenerally annular extension of wall I1, this extension being indicatedat 6I in the drawings and being partly cut away to admit gear 5I. Themember 60 providing wall I8 is secured to the extension 6I by screws 62.overhanging lip 63 having a receptacle 64 therein is formed on member 60to receive the turned up edge of a spun metal cover 66. This ver ispositioned between the lmember 60 and a ange 61 formed upon andextending about the periphery of the member providing wall I1. A flange68 is ,formed upon the member providing wall I6, the

two flanges being secured together as by screws 69 to secure the unittogether. 4

The screws 62 force the cover to spring into place whereby an oil tightseal is provided between the cover and the casing proper.

The cover 66 is made of light sheet steel. This enables the weight ofthe entire unit to be reduced and yet a satisfactory unit provided. Byreason of the resilient nature of the steel, the annular shape of thecover, andthe inclusie of l bearing 38 upon a reduced portion 1lthereof, and

sprocket 4| as having a relatively small hub 12. Because shaft 36 isrelatively small in mass, it can be readily manufactured as a specialpart to vaccommodate sprockets, pulleys or gears of various hub size,bearing 38 and plate I8 being readily' accommodated to this.

In- Figure 5 Ihave shown'the unit in combination with a prime mover-sucl as an electric motor 16 havinga drive shaft 11 carrying a sprocket18 thereon. A metal casing, indicated generally at 19, is formed with anannular portion 8l engagingA and fitting upon the spun metal case 66.This case extends to surround the sprocket 18 upon the motor shaft sothat an entire unit, enclosed to protect the workman, is provided. Sucha case also protects the sprockets 'and chains, suitable lubricatingmeans being provided for the chain if desired as a drip oil feed.

Since the speed change units are mounted upon a shaft without a base,suitable means are provided to resist'their reactive torque. This isusually accomplished by attaching an arm 82 to the case and by extendinga pin B3 through suitable apertures provided in the ends of the arms andthrough an aperture in the flanges 61 and E8 on the case. port.' Forexample, in Figure 6 I have shownV it as extending to and engaging anear lill on motor base 16. The motor 16 is slidable along support 84,slots 102 in the base of the motor'fcooperating with suitable studs (notshown) to hold and position the motor. Reactive torque causes arm 82 topush the motor base away from the unit and increase the center to centerdistance so that th tension on the belt is increased.

Referring to Figures 6 and 7, these illustrate one'of the many uses towhich a unit of this type can be placed. As appears there, a supportstructure 84 is mounted upon the side of a tank Motor 16 is mounted uponthis support, while the unit is mounted upon shaft 1 which is supportedin a support structure provided by channels 9| and plate 92. Plate 92carries a suitable bearing 93 supporting the shaft 1 for rotation. Shaft1 can depend into the tank to rotate, for example, an agitator, as in amayonnaise tank. Hub 9 engages a thrust bearing 94. A receptacle 9B isformedupon the upper surface of plate 92 and an annular member 91 ismounted upon' that member providing wall I6 to depend into thereceptacle 96. Receptacle 96 is usually filled With a suitable sealingliquid, such as mercury.

A similar sealing receptacle is formed beneath bearing 93, the platecontinuing with a depending annulus 98 'formed thereon and spaced fromthe shaft 1, this annulus extending into a receptacle provided by member99. The receptacle in member 99 is usually filled with mercury toprovide a construction. Y

The sheet'metal case enables the unit weight to be decreased 30 to 40%.This decrease is even more effective because it is from the outboardside of the unit (Figure 3), where the extending shaft isunsupported.The primary reduction en- The arm is extended to a suitable supab'lesthe gearing in the case to be run atlower I speed and therefore moreefficiently, particularly in the case of helical gearing.

This case is a continuation in part of my applications ser. Nos. 113,246and 113,247 of November on said shaft, a casing structure including afirst,

a second and a third wall, said walls being substantially parallel andspaced apart, 'bearing means supporting said rst wall on said gear hubon one side of said web, bearing means supporting said second wall onsaid gear hub on the other side of said web, a second shaft, bearingmeans in f 1 said second wall for said second shaft, bearing means insaid third wall for said second shaft, gear means on said second shaftbetween said two last mentioned bearing means, and'gearing connectingsaid first and Second gears to eect a speed change therebetween.

2. In a device of the Vcharacter described, a :first shaft, a, firstgear having a hub connected to a. gear portion by a Web, means securingsaid gear on said shaft, a casing structure including a first,`

a second and a third wall, said walls being substantially parallel andspaced apart, said rst and second walls being anged along said rst shaftwith the flanges extending toward each other, bearing means supportingsaid first 'wall on said gear hub on one side of said web, between theflange on said rst wall and said hub', bearing means supporting saidsecond wall on said gear hub on the other 4side of said web between thetween.

' 3. In a device of thecharacter described, a rst shaft, a first gearhaving aV-hub connected to a gear portion bya Web, means securing saidgear on said shaft, a casing .structure including a first.'

a second and a third wall, said walls being substantially parallel andspaced apart, bearing means supporting said rst wall on said gear hub onone side of said web, bearing means supporting said second wall on saidgear hub on the other side of said web, a second shaft, 'bearing meansin said second Wall for said second shaft, bearing means in said thirdwall for said second shaft, gear means on said second shaft between saidtwo last mentioned bearing means, a third shaft mounted in said firstand second walls with an end thereof extending beyond said second Wall.

and gearing carried on said end and on said last' mentioned shaft andconnecting said first and second gears.

4. In combination,` a first wall member, a second wall member, each ofsaid members having a portion extending toward the other, a. bearingmeans supported in eachV extending portion, a first gear having a faceoverhanging the extending portions and a hollow hub mounted for rotationin said bearing means, a third wall member, an extension on said secondwall member supporting said third wall member, a shaft substantiallycoaxial with said hub, bearing means in said second Wall member and saidthird wall tion in said bearing means, a third wall member,

an extension on said second wall member supporting saidv third wailmember, a shaft substantially coaxial with said hub, said shaft beingrelieved at least partially to admit an end of a support shaft passedthrough said hub, bearing means in said second wall member and saidthird wall member for supporting said shaft, a secondr gear on saidshaft between said two last mentioned bearing means, 'and gearingconnecting said rst and second gears.

6. In a device of the character described, a housing and supportstructure having a substantially continuous peripheral flange circularin iormextending therefrom at a point spaced from 'at least one side ofsaid housing and support structure, a member carried by said housingvand support structure and vhaving a substantially circular peripheralflange thereon substantially concentric with said iirst mentioned flangebut in a plane substantially parallel to but spaced from the plane 'ofsaid first mentioned flange, and a substantially circular sheet metalhousing having a central rim and opposite sides substantially par-?ij/allel to each other and depending from said rim',

one side being engaged with the Bange on said housing and the other sidebeing engaged with the ange on the member.

7. In a device of the character described, a housing and supportstructure having a substantially continuous peripheral flange extendingtherefrom at a point spaced from at least one side ofsaid housing andsupport structure, a membercarried by said housing and support structureand havinga substantially circular peripheral flange thereon, asubstantially circular sheet metal housing having a central rim andopposite sides substantially parallel to each other and depending `fromsaid rim. one side being engaged-with the flange on said housing and theother side being engaged with the iiange on the member, and means forsecuring said member to said housing and support structure to move saidopposite housing sides together and compress said housing whereby atight junction is provided between the housing sides and the angesengaging the same.

8. In a device of the character described, a housing and supportstructure including an outside wall on one side of said housing and ahousing extension on the other side of said housing, an outside wallmember carried by said extension, and a sheet metal housing having a rimportion and opposite sides thereon extending inwardly from the rim andnormally away from each other, said housing sides being engaged with andexed so as to be substantially parallel between said outside wall memberand said housing and support structure.

JOSEPH D. CHRISTIAN.

